arXiv Computation and Language

Concentrated Causal Influence, Distributed Diagnostic Information: Cognitive Impairment Decisions in Large Audio-Language Models

Large audio‑language models can detect cognitive impairment from speech, but it was unclear which internal components drive this decision or how much impairment information is stored in their representations. The study identifies class‑contrastive activation neurons (CICNs) in decoder MLPs and shows that ablating small CICN sets causes significant, class‑directed prediction shifts in several models, while CICN activations can be linearly read out to achieve high AUC scores. These findings demonstrate that a concentrated set of neurons exerts causal control over CI decisions, whereas diagnostic information is broadly distributed across the model’s representations.

arXiv Machine Learning
Oct 16

Cross-subject decoding of imagined speech from scalp EEG: a leakage-controlled evaluation on three public corpora

The study evaluated whether imagined speech decoded from scalp EEG can transfer across individuals using three public datasets. Across 482 participant pairs, cross‑subject decoding accuracy was essentially at chance, while within‑subject decoding only surpassed chance in one dataset. The results suggest that imagined‑speech content does not generalize between people and that larger single‑condition datasets are more beneficial than further model development.

By Blessing Isoyiza Adeika, Onyema Osuagwu
arXiv Computation and Language
Sep 14

Quantifying Consonant Contributions to Word Intelligibility via Acoustic Masking

The study introduces a scalable acoustic‑masking method to quantify how much each consonant contributes to word intelligibility. By silencing individual consonants in isolated words and measuring misrecognition rates with three ASR models, the authors define a mask‑induced misrecognition rate (MMR). Across English, Spanish, German, and Czech, MMR negatively correlates with phoneme frequency and positively with functional load, revealing that consonant importance varies by language.

By Eunjung Yeo, Kwanghee Choi, Krupaben Kothadia, Visar Berisha, Julie M. Liss, David R. Mortensen, David Harwath
arXiv AI
Oct 12

Does Location Matter? A Black-Box Causal Audit Reveals Model-Dependent Audio Grounding in LALM Hallucination

The paper investigates how large audio‑language models (LALMs) hallucinate objects by affirming sounds that are not present. Using a black‑box causal test, the authors isolate and remove the claimed evidence region via spectral gating and compare the effect against a random‑window control across a 2×2×2 grid on three LALMs. The study finds that localization of evidence improves detection over random removal, that raw detection values are model‑dependent, and that contrastive decoding combining blank and language‑prior contrasts can significantly boost accuracy, but a unified causal‑grounding profile does not transfer between models.

By Mohammad Khalooei, Mohammad Sabokrou